Optical microscopy is without doubt one of the most beneficial yet less than applied instruments for interpreting fiber bolstered polymer matrix composites. This hands-on tutorial publication covers every thing: pattern education, microscopic ideas, and functions. the ability of optical microscopy to review the microstructure of those heterogeneous, anisotropic fabrics is illustrated with over one hundred eighty complete colour photos.

In general, salt rocks tend to deform plastically by flowage, while intercalated carbonates, anhydrite and "clay" exhibit elastic behavior until they rupture. "Clay" beds encountered in deeply buried evaporite sequences have been completely dehydrated during compaction; therefore, they are, in fact, dry shales or mudstones, and they behave accordingly when deformed after consolidation. The latter point is emphasized because, from time to time, writers are mis­ led by the term "clay" and postulate plastic behavior, as would be expected if the shales and mudstones encountered in mines were wet, as found in near-surface deposits.

282), similar to what is observed on Recent salt domes. These observations are of particular interest regarding the flowage of salt into underground openings in salt deposits excavated in mining operations; for this reason, such observations are dealt with in some more detail in the following sub­ section. 4 Salt glaciers Stöcklin (1968, pp. 158-159) may be quoted as follows: "The Middle East is one of the classic regions of salt geology. Salt features, which in other parts of the world had to be pieced together during decades of toilsome work in dark mine shafts, are magnificently displayed in full daylight in the Middle East.

In marginal areas, some of the clay laminae of central basin areas reach thicknesses up to 10 cm, suggesting conditions similar to those reported above for deeper parts of the Prairie Evaporite basin. Such clay layers are of particular importance for their rock-mechanical effects in both the Stassfurt potash bed and the Prairie Evaporite potash beds (see Chapter 00). This statement also holds true for the potash beds mined in two other major potash mining districts, the Soligorsk district of Belo-Russia and the Upper Rhine district of Alsace, France.